PISTON KIT 99-18 YZ250 66.40 B, WOSSNER 8216DB YAMAHA MX, 2 RING PISTON

This Wossner piston kit with a 66.41mm bore (+0.01mm oversize, actual size 66.36mm) is designed for Yamaha YZ250 models from 1999 to 2018. The forged 2-ring piston is engineered for high-performance applications, offering strength, thermal efficiency, and reliability in demanding two-stroke engines.

Features

• Forged construction for maximum strength and durability

• Optimised for effective heat transfer from combustion chamber to cylinder walls

• Elliptical shape ensures uniform bearing surface and reduces the risk of piston collapse under thermal stress

• Precision-made in Germany

Specifications

• Bore size: 66.41 mm

• Actual piston size: 66.36 mm

• Display (cm³): 249

• Stroke (mm): 54.10

• Clearance (mm): 0.06

• Compression ratio: 2-stroke (Wossner and OEM)

• Compression height (mm): 28.00

Vehicle Fitments

• 1999–2018 Yamaha YZ250

Included Components

• Piston: Wossner PN# 8216DB (2-ring)

• Lock: PN# CW18

• Pin: PN# WP033

• Ring Set: PN# RSB6640 x 2

• Rod: PN# P2028